@primary-color: #4eabc6; // 全局主色
@link-color: #4eabc6; // 链接色
@fixed-content: 1200px; // 页面主体宽度
@screen:        ~"only screen";
@screen-md:     1200px;  //中等屏幕
@screen-sm:     768px;  //小屏幕
@md-down:      ~"@{screen} and (max-width:@{screen-md})"; //平板响应节点
@sm-down:      ~"@{screen} and (max-width:@{screen-sm})"; //手机响应节点